Liner segment



March 18, 1941.

c. B. CUSHWA ET AL LINER SEGMENT Original Filed A ril :50, 1938 a W w 5 RU m NB ws me w h C 7 and Thomas LII/f1 he Reissued Mar. 18, 1941 y D is'TAT ES PATENT OFFICE LINER S EGMEN T 'CharlesB. Cushwa and Thomas L. White, Youngstown. Ohio, assignors t o The Commercial Shearing &- Stamping 'Company, a corporation of Ohio Original No. 2,181,508, dated November 28,1939,

Serial'No. 205,30

for reissue Glaims.

This invention relatesktolinings. for earthborlugs and, in particular, .to a .liner segment adapted to bejformedfromsteel plate. and to be assemblejdendto. end with other similarsegments forming continuous. lining.rlngs. .Such rings are assembled side -by side in .a .manner toform a complete lining.

. Numerous forms. of liner segments have. been .proposed "heretofore and it .isthe principal object of.our'invention to improveupon-the segments which havebeen used previously bothfrom the standpoint of economy. of manufacture-and ease and convenience .in.erection,.while.. at. the same F time providing a segment of ample strength to support the load .to which linings are usually subjected.

Linings for. earth borings are subject to certain well defined 'forces, suchas ring thrust, .ring bending, bending of segments, etc. Ring thrust is the circular. thrustgoing around the ring setting up compression stresses in the metal. This ring thrust is distributed over the sectional area of the segment and must be transmitted across the joints between the segments of each ring. Bending is caused by unequal loading of the ring and is resisted by the section modulus of the segment. The joints between segments of each ring must be strong enough to withstand the bending force. Staggering of the joints in the adjacent courses is of assistance in this respect, each course acting as a splice for the adjacent course. Local bending of individual segments is resisted by the section modulus of the segments taken circumferentially of the lining. It will be seen, therefore, that the strength of the joints is of extreme importance.

In a preferred form of the invention our liner segment comprises a curved plate having stiffening corrugations extending therealong, pref- 40 erably though not necessarily throughout the entire length thereof. Each segment is overlapped by one of the other adjacent segments. These structural features provide the strength necessary to resist the forces above mentioned. We provide means for rigidly connecting the segments end to end, as will be described in greater detail hereafter, with reference to the accompanying drawings illustrating a preferred embodiment. In the drawing:

Fig. 1 is a partial plan view of a lining composed of segments according to our invention;

Fig. 2 is a partial sectional View taken along the line 11-11 of Fig. 1;

Fig. 3 is a similar view taken along the line II IIII of Fig. 1;

4, April 30,. 1938. Application April 20, 1940, vSeijial No.- 330,800

(DIEM-45) Fig. 4 is a radial sectional viewtaken through asegment alongthe line of .theboltholes adjacent one end;

Fig. 5 is a similar view taken along the line of the bolt holes adjacent the other endyand Fig. 6 .is a transverse-sectional View showing a modification.

Referring. now in detail to the drawing, a lining for a tunnel or the like in accordancewith the invention is indicated generally at In. The lining is composed of segments 30 assembled end to end to form rings. These rings are built .upin side by'side relationto the desired length within the tunnel or other boring.

. gations 32 extending throughout the length thereof,.are produced by suitably shaping steel plates. Eachsegment 30 is curved longitudinally and has intermediate transverse reinforcing members 30a. Opposite ends of each segment areprovided with'frusto conical depressions or protuberances33 and -34 so-shapedand dimensioned' that they form mating portions, as shown in Figs. 2 and 3, when the ends of adjacent segments are lapped for connection as by bolts 35 extending through alined holes in the depressions 33 and 34. The depressions are preferably formed in the bottoms of the troughs formed by the corrugations which are substantially fiat. For convenience in assembling the segments, nuts 36 are welded in the depressions 33 at one end of each segment. The bolts 35 may thus be inserted from inside the lining and screwed home tight without any difiiculty. Bolts 31 extending through alined holes in side walls 3| serve to connect adjacent rings of the lining.

It will be apparent from the foregoing description that the segment shown in the drawing makes it possible, at relatively low cost, to provide a strong, rigid lining for earth bores characterized by tight joints and relatively light weight. The facility with which the lining may be erected is a further important advantage because the work of assembly is performed within the lining where working space is very limited.

The segment shown is also characterized by the additional advantage of still lower cost in that no end walls are employed. The mating recesses 33 and 34 make the end-to-end joints efiicient in transmitting thrust and the bolts passing through the crests and troughs of the corrugations are likewise very efficient in transmitting bending stress.

A further form of the invention is illustrated in Fig. 6. This form is similar to that of Figs. 1

The segments30, with side walls 3i and corru-' through 5 in all respects except that it has no side wall as such, the edges of the segments of adjacent rings being lapped as at 40, one edge of each segment being pressed downwardly as at 4| to permit such lapping. The lapped edges are connected by bolts 42 and the nuts 43 c0- operating therewith may be welded to the edges of the segments in alinement with the bolt holes to facilitate assembly.

While we have illustrated and described herein only a preferred form of the invention with a modificaton thereof, it will be understood that various other changes in the invention disclosed may be made without departing from the spirit thereof or the scope of the appended claims.

We claim:

1. A liner segment comprising a skin plate curved along one dimension and having corrugations extending along said dimension, depressions formed adjacent one end of the plate and protuberances at the other, a pair of said segments being adapted to be assembled end to end in partly lapped relation wherein the protuberances at one end of a segment mate with the depressions in the end of the adjacent segment, said depressions and protuberances being disposed at the crests and troughs of said corrugations.

2. A lap joint connecting the edge of one plate to the edge of an adjacent plate, said plates being curved along their dimension perpendicular to their lapping edges and having corrugations extending in the direction of curvature, said joint including depressions spaced apart along the lapping edge of said'one plate, protuberances similarly spaced along the lapped edge of the adjacent plate, said protuberances nesting in said depressions when the edge of said first-mentioned plate is in lapping relation to the edge or said adjacent plate with their corrugations nesting, and means securing the lapped edges of said plates together, said depressions and protuberances being tapered whereby they nest tightly.

3. A liner segment comprising a metal plate curved along one dimension and having corrugations extending in the direction of said dimension, forming open troughs exteriorly and interiorly of the segment, said troughs converging toward their bottoms whereby the ends of a pair of segments disposed in end-to-end, overlapping relation may be brought together and nested by sidewise movement, the ends of the corrugations being open to permit such nesting, and protuberances and depressions in the bottoms oi said troughs adjacent the ends thereof, the protuberances on one segment being adapted to interfit with the depressions on another segment disposed in lapped, end-to-end, nesting relation therewith.

4. A liner segment comprising a metal plate curved along one dimension and having corrugations extending in the direction of said dimension, forming open troughs exteriorly and interiorly of the segment, said troughs converging toward their bottoms whereby the ends of a pair of segments disposed in end-to-end, overlapping relation may be brought together and nested by sidewise movement, the ends of the corrugations being open to permit such nesting, and protuberances and depressions in the bottoms of said troughs adjacent the ends thereof, the protuberances on one segment being adapted to interflt with the depressions onanother segment disposed in lapped, end-to-end, nesting relation therewith, said protuberances and depressions having holes therein adapted to receive fasteners for securing adjacent plates together, the holes being so located as to be in alinement when the protuberances and depressions interfit.

5. A liner segment as defined by claim 3 characterized by nuts welded to the segments back of said protuberances.

CHARLES B. CUSHWA. THOMAS L. WHITE. 

